title: Hypoxia in Manila Bay, Philippines during the northeast monsoon.
abstract: Herein we present results from one of the first extensive bay-wide oceanographic surveys of Manila Bay, wherein 31 stations were sampled during the northeast monsoon (cold and dry season). A band of hypoxic bottom water (dissolved oxygen<2.8 mg/L) spanned the midsection of the bay from east to west. Bottom nitrate concentrations (5.7-16.8 μM; avg. 11.1 μM) and total organic carbon values in sediments (1.7-3.1%; avg. 2.4%) were high in the midsection, which coincided with the band of hypoxic bottom water. Physical processes and site-specific accumulation of organic material likely lead to hypoxic conditions in Manila Bay, even during the northeast monsoon period when the water column is relatively well mixed. The results of this study complement the previously reported widespread hypoxia that occurs during the rainy season. Thus, hypoxia may be pervasive in the bay throughout the year, although it varies in intensity and spatial extent.
authors.affiliation: Marine Science Institute, University of the Philippines, Diliman, Quezon City 1101, Philippines. gilj@upmsi.ph
authors.forename: Gil S
authors.initials: GS
authors.lastname: Jacinto
authors.forename: Lara Patricia A
authors.initials: LP
authors.lastname: Sotto
authors.forename: Maria Isabel S
authors.initials: MI
authors.lastname: Senal
authors.forename: Maria Lourdes
authors.initials: ML
authors.lastname: San Diego-McGlone
authors.forename: Ma Teresa L
authors.initials: MT
authors.lastname: Escobar
authors.forename: Atsuko
authors.initials: A
authors.lastname: Amano
authors.forename: Todd W
authors.initials: TW
authors.lastname: Miller
mesh_terms: D002734:Chlorophyll / Q000032:analysis; D000077194:Chlorophyll A; D004784:Environmental Monitoring; D005068:Eutrophication; D019015:Geologic Sediments / Q000737:chemistry; D009792:Oceans and Seas; D010100:Oxygen / Q000032:analysis; D010679:Philippines; D054712:Salinity; D012621:Seasons; D012623:Seawater / Q000737:chemistry*; D013696:Temperature; D014876:Water Pollution / Q000032:analysis* / Q000706:statistics & numerical data; D014887:Weather
chemical_list: D002734:Chlorophyll; D010100:Oxygen; D000077194:Chlorophyll A